The InterWiki? map is taken from the the <verbatim> block in InterWikiMap, but that page must be locked for it to work. This denies a potential hacker the ability to nefariously change every InterWiki? link to point to some evil URL. If no map is found in InterWikiMap (or the page is not locked), PhpWiki will fall back to using the file lib/interwiki.map in your phpwiki distribution. The InterWiki? map file in use at PhpWiki: can be viewed at http://phpwiki.sf.net/interwiki.map.
The map file is manually updated. It is based upon and periodically synchronized with UseMod's InterMap but it is not quite identical. One notable difference from UseMod: is that PhpWiki supports '%s' within the URLs in the map--see the entry for RFC for an example of how this works.
The "Category" moniker is a special entry which allows one to link a wiki page to a Category page without creating a back-reference. Thus Category:Category links to the CategoryCategory? page, yet this page won't show up in the back-links listing of CategoryCategory?.
